The purpose of this note is to shed some light on the relationship between the Copeland rule and the Condorcet principle in those cases where there does not exist a Condorcet winner. It will be shown that the Copeland rule ranks alternatives according to their distances to being a Condorcet...

The purpose of this paper is to provide a binary comparison of two distance-based preference aggregation rules, Slater's rule and Kemeny''s rule. It will be shown that for certain lists of individual preferences the outcomes will be antagonistic in the sense that what is considered best...

In this paper we compare a minisum and a minimax procedure as suggested by Brams et al. for selecting committees from a set of candidates. Using a general geometric framework as developed by Don Saari for preference aggregation, we show that antipodality of a unique maximin and a unique minisum...

A cake is a metaphor for a heterogeneous, divisible good, such as land. A perfect division of cake is efficient (also called Pareto-optimal), envy-free, and equitable. We give an example of a cake in which it is impossible to divide it among three players such that these three properties are...

We show how ultrafilters can be used to prove a central impossibility result in judgement aggregation introduced by Nehring and Puppe (2005), namely that for a logically strongly interconnected agenda, an independent and monotonic judgement aggregation rule which satisfies universal domain,...

The trade-off between equity and efficiency is analyzed in a geometric framework for the problem of committee selection, which has recently attracted interest in the social choice literature. It is shown that this trade-off can be maximal in the precise sense of the antipodality of the outcomes...

In this paper we compare a minisum and a minimax procedure as suggested by Brams et al. for selecting committees from a set of candidates. Using a general geometric framework as developed by Don Saari for preference aggregation, we show that antipodality of a unique maximin and a unique minisum...

This paper compares binary versions of two well-known preference aggregation methods designed to overcome problems occurring from voting cycles, Copeland's (1951) and Dodgson''s (1876) method. In particular it will first be shown that the Copeland winner can occur at any position in the Dodgson...